It is now documented that dental caries in persons aged 5-17 years old are declining. These reductions have occurred for a sufficient number of years so several age cohorts of children who experienced reductions in caries are now adults. Some evidence suggests that adults maintain these caries reductions. Less evidence is available regarding whether or not these caries reductions are maintained throughout life. Reductions in tooth loss also occurred in U. S. adults between 1974 and 1985. This continues a trend which was apparent in the 1960. Reductions in the percentage of the population experiencing total tooth loss (edentulism) is especially pronounced. This study is analyzing the impact of these changes in the extent of dental caries on the utilization of dental services. Longitudinal data from the Rand Corporation Health Insurance Experiment will be used to estimate the probability of subjects enrolled in the experiment attending a dental office over different time periods. For those subjects who attended a dental office, a demand function will be estimated to predict the amount of dental expenditures over these same time periods. The prevalence and extent of dental and periodontal conditions will be controlled. Analyses are nearing completion. Several reports will be published.